CHANGELOG: add xenstore quota support

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>

CHANGELOG.md

@@ -9,6 +9,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 ### Changed
 
 ### Added
+ - Support for per-domain Xenstore quota in C xenstored (includes
+   xenstore-stubdom), libxl and xl.
  - On x86:
    - Support for Bus Lock Threshold on AMD Zen5 and later CPUs, used by Xen to
      mitigate (by rate-limiting) the system wide impact of an HVM guest